First Advisor

Martin Lafrenz

Date of Publication

Fall 12-12-2013

Document Type

Thesis

Degree Name

Master of Science (M.S.) in Geography

Department

Geography

Language

English

Subjects

Dam retirement -- California -- Lassen Volcanic National Park -- Case studies, Soil restoration -- California -- Lassen Volcanic National Park -- Case studies, Revegetation -- California -- Lassen Volcanic National Park -- Case studies, Dam retirement -- Environmental aspects -- California -- Lassen Volcanic National Park -- Case studies

DOI

10.15760/etd.1513

Physical Description

1 online resource (v, 50 pages)

Abstract

Dam removal is increasing as dams age, yet little is understood about the pedogenic response to dam removal. This study reports on the edaphic changes of reservoir sediments and vegetation cover one year following removal of a small earthen dam in Northern California. In August 2012, I sampled surface sediments from the former Dream Lake reservoir in Lassen Volcanic National Park, and compared their physical and chemical properties with soil samples from two reference sites. I also estimated percent cover of vegetation in the former reservoir and reference sites. My results show that the reservoir was under reduced conditions, as determined by gleyed soil color and a higher pH when compared to reference samples. In contrast to reservoirs on larger river systems which tend to be sinks for organic matter, Dream Lake showed a reduction in organic matter when compared to reference locations.

My results suggest reservoirs created by dams cannot be considered to have similar sediment properties, namely increases in organic material. Unlike other studies that found former impoundments invaded by non-native species, the former Dream Lake site has been colonized by native grasses, sedges, and rushes. This study documents the edaphic properties and vegetation response of a small reservoir one year after dam removal, and suggests a more thorough investigation of those properties prior to undertaking costly restoration of these highly dynamic systems.

Rights

In Copyright. URI: http://rightsstatements.org/vocab/InC/1.0/ This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).

Persistent Identifier

http://archives.pdx.edu/ds/psu/10466

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